N-heterocyclic germylenes: structural characterisation of some heavy analogues of the ubiquitous N-heterocyclic carbenes

The X-ray crystal structures of three N-heterocyclic germylenes (NHGes) have been elucidated including the previously unknown 1,3-bis(2,6-dimethylphenyl)diazagermol-2-ylidene (1). In addition, the X-ray crystal structures of the previously synthesised 1,3-bis(2,4,6-trimethylphenyl)diazagermol-2-ylidene (2) and 1,3-bis(2,6-diisopropylphenyl)diazagermol-2-ylidene (3) are also reported. The discrete molecular structures of compounds 1 to 3 are comparable, with Ge-N bond lengths in the range 1.835-1.875 Å, while the N-Ge-N bond angles range between 83.6 and 85.2°. Compound 2 was compared to the analogous N-heterocyclic carbene species, 1,3-bis(2,4,6-trimethylphenyl)imidazol-2-ylidene (IMes). The major geometrical difference observed, as expected, was the bond angle around the divalent group 14 atom. The N-Ge-N bond angle was 83.6° for compound 2 versus the N-C-N bond angle of 101.4° for IMes. The Sn equivalent of (1), 1,3-bis(2,6-dimethylphenyl)diazastannol-2-ylidene (4), has also been synthesised and its crystal structure is reported here. In order to test their suitability as ligands, compounds 1 to 3 were reacted with a wide range of transition metal complexes. No NHGes containing metal complexes were observed. In all cases the NHGe either degraded or gave no reaction

Particle acceleration in tangential discontinuities by lower hybrid waves

We consider the role that the lower-hybrid wave turbulence plays in providing the necessary resistivity at collisionless reconnection sights. The mechanism for generating the waves is considered to be the lower-hybrid drift instability. We find that the level of the wave amplitude is sufficient enough to heat and accelerate both electrons and ions

The Dynamic Formation of Prominence Condensations

We present simulations of a model for the formation of a prominence condensation in a coronal loop. The key idea behind the model is that the spatial localization of loop heating near the chromosphere leads to a catastrophic cooling in the corona (Antiochos & Klimchuk 1991). Using a new adaptive grid code, we simulate the complete growth of a condensation, and find that after approx. 5,000 s it reaches a quasi-steady state. We show that the size and the growth time of the condensation are in good agreement with data, and discuss the implications of the model for coronal heating and SOHO/TRACE observations.Comment: Astrophysical Journal latex file, 20 pages, 7 b-w figures (gif files

Future possibilities in the prevention of breast cancer: Luteinizing hormone-releasing hormone agonists

The cyclic production of estrogen and progesterone by the premenopausal ovary accounts for the steep rise in breast cancer risk in premenopausal women. These hormones are breast cell mitogens. By reducing exposure to these ovarian hormones, agonists of luteinizing hormone-releasing hormone (LHRH) given to suppress ovarian function may prove useful in cancer prevention. To prevent deleterious effects of hypoestrogenemia, the addition of low-dose hormone replacement to the LHRH agonist appears necessary. Pilot data with such an approach indicates it is feasible and reduces mammographic densities

Model-Based Signal Processing for Laser Ultrasonic Signal Enhancement

The use of laser-based ultrasonics in the testing of materials and structures offers various advantages over more traditional ultrasonic methods, but is often less sensitive when applied to real materials. Although high energy laser pulses can generate large ultrasonic displacements, nondestructive evaluation requires that the ablation regime be avoided, thus limiting the amount of optical energy which may be used. For this reason, signal processing of laser generated ultrasonic waveforms detected using laser interferometers may be required to extract the desired information from a nondestructive laser ultrasonic test. A model-based signal processing technique offers a way to enhance the signal-to-noise ratios significantly for ultrasonic waveforms obtained using laser-based systems with the generation of the ultrasound occurring in the nondestructive thermoelastic regime

Towards an untrepreneurial economy? The entrepreneurship industry and the rise of the veblenian entrepreneur

What is driving the declining quality of innovation-driven entrepreneur-ship? In this paper, we argue the growing entrepreneurship industry is an important yet overlooked explanation. This rapidly growing industry has transformed the nature of entrepreneurship and encouraged a particular form of low-quality entrepreneurship. It has done so by leveraging the Ide-ology of Entrepreneurialism to mass-produce and mass-market products that make possible what we term Veblenian Entrepreneurship. This is entrepreneurship pursued primarily as a form of conspicuous consumption. Aside from lowering average entrepreneurial quality, Veblenian Entrepreneurship has a range of (short-run) positive and (medium and long-run) negative effects for both individuals and society at large. We argue that the rise of the Veblenian Entrepreneur has contributed to creating an increasingly Untrepreneurial Economy. That is an economy which superficially appears innovation-driven and dynamic, but is actually rife with inefficiencies and unable to generate economically meaningful growth through innovation.

Survival of patients with small cell lung cancer undergoing lung resection in England, 1998–2009

Introduction: Chemotherapy or chemoradiotherapy is the recommended treatment for small cell lung cancer (SCLC), except in stage I disease where clinical guidelines state there may be a role for surgery based on favourable outcomes in case series. Evidence supporting adjuvant chemotherapy in resected SCLC is limited but this is widely offered. Methods: Data on 359 873 patients who were diagnosed with a first primary lung cancer in England between 1998 and 2009 were grouped according to histology (SCLC or non-SCLC (NSCLC)) and whether they underwent a surgical resection. We explored their survival using Kaplan-Meier analysis and Cox regression, adjusting for age, sex, comorbidity and socioeconomic status. Results: The survival of 465 patients with resected SCLC was lower than patients with resected NSCLC (5-year survival 31% and 45%, respectively), but much higher than patients of either group who were not resected (3%). The difference between resected SCLC and NSCLC diminished with time after surgery. Survival was superior for the subgroup of 198 'elective' SCLC cases where the diagnosis was most likely known before resection than for the subgroup of 267 'incidental' cases where the SCLC diagnosis was likely to have been made after resection. Conclusions: These data serve as a natural experiment testing the survival after surgical management of SCLC according to NSCLC principles. Patients with SCLC treated surgically for early stage disease may have survival outcomes that approach those of NSCLC, supporting the emerging clinical practice of offering surgical resection to selected patients with SCLC

How primary care can contribute to good mental health in adults.

The need for support for good mental health is enormous. General support for good mental health is needed for 100% of the population, and at all stages of life, from early childhood to end of life. Focused support is needed for the 17.6% of adults who have a mental disorder at any time, including those who also have a mental health problem amongst the 30% who report having a long-term condition of some kind. All sectors of society and all parts of the NHS need to play their part. Primary care cannot do this on its own. This paper describes how primary care practitioners can help stimulate such a grand alliance for health, by operating at four different levels - as individual practitioners, as organisations, as geographic clusters of organisations and as policy-makers

Noise storm continua: power estimates for electron acceleration

We use a generic stochastic acceleration formalism to examine the power $L_{\rm in}$ (${\rm erg s^{-1}}$) input to nonthermal electrons that cause noise storm continuum emission. The analytical approach includes the derivation of the Green's function for a general second-order Fermi process, and its application to obtain the particular solution for the nonthermal electron distribution resulting from the acceleration of a Maxwellian source in the corona. We compare $L_{\rm in}$ with the power $L_{\rm out}$ observed in noise storm radiation. Using typical values for the various parameters, we find that $L_{\rm in} \sim 10^{23-26}$ ${\rm erg s^{-1}}$, yielding an efficiency estimate $\eta \equiv L_{\rm out}/L_{\rm in}$ in the range 10^{-10} \lsim \eta \lsim 10^{-6} for this nonthermal acceleration/radiation process. These results reflect the efficiency of the overall process, starting from electron acceleration and culminating in the observed noise storm emission.Comment: Accepted for publication in Solar Physic

Women and Illegal Activities: Gender Differences and Women's Willingness to Comply Over Time

In recent years the topics of illegal activities such as corruption or tax evasion have attracted a great deal of attention. However, there is still a lack of substantial empirical evidence about the determinants of compliance. The aim of this paper is to investigate empirically whether women are more willing to be compliant than men and whether we observe (among women and in general) differences in attitudes among similar age groups in different time periods (cohort effect) or changing attitudes of the same cohorts over time (age effect) using data from eight Western European countries from the World Values Survey and the European Values Survey that span the period from 1981 to 1999. The results reveal higher willingness to comply among women and an age rather than a cohort effect. Working Paper 06-5